Mycobacterium paratuberculosis - rod prokaryote (bacterium)
Copyright 2002 Dennis Kunkel Microscopy, Inc.
Caption: Mycobacterium paratuberculosis - Gram-positive, rod prokaryote (dividing). Genetically M. paratuberculosis is almost identical to Mycobacterium avium. However phenotyically it grows much more slowly, requires an iron-transport chemical known as mycobactin for in vitro growth, forms rough colonies on solid agar media, and infects mammals instead of birds. While sharing many genetic similarities with M. avium, M. paratuberculosis is less closely linked genetically to pathogenic mycobacteria in the TB complex. M. paratuberculosis can grow only inside animal cells where it assimilates iron from its host's cells, most often immune cells called macrophages. Like other mycobacteria, M. paratuberculosis has the capacity to thrive inside macrophages. Thus, it is an obligate parasitic pathogen of mammals; a zoonotic microorganism that most commonly infects ruminant animals. Also associated with Johne's disease. Magnification*: x3,000 Type: SEM
*(Magnifications are based on a 35mm slide image of 24mm in the narrow dimension.)